Journal articles: 'Energy Code Smell'

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Almadi, Sara H. S., Danial Hooshyar, and Rodina Binti Ahmad. "Bad Smells of Gang of Four Design Patterns: A Decade Systematic Literature Review." Sustainability 13, no. 18 (September 14, 2021): 10256. http://dx.doi.org/10.3390/su131810256.

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Gang of Four (GoF) design patterns are widely approved solutions for recurring software design problems, and their benefits to software quality are extensively studied. However, the occurrence of bad smells in design patterns increases the crisis of degenerating design patterns’ structure and behavior. Their occurrences are detrimental to the benefits of design patterns and they influence software sustainability by increasing maintenance costs and energy consumption. Despite the destructive roles of bad smells in such designs, there are an absence of studies systematically reviewing bad smells of GoF design patterns. This study systematically reviews a 10-year state of the art sample, identifying 16 studies investigating this phenomenon. Following a thorough evaluation of the full contents, we observed that the occurrence of bad smells have been investigated in proportion to four granularity levels of analysis: Design level, category level, pattern level, and role level. We identified 28 bad smells, categorized under code smells and grime symptoms, and emphasized their relationship with GoF pattern types and categories. The utilization of design pattern bad smell detection approaches and datasets were also discussed. Consequently, we observed that the research phenomenon is growing intensively, with a prominent focus of studies analyzing code smell occurrences rather than grime occurrences, at various granularity levels. Finally, we uncovered research gaps and areas with significant potentials for future research.

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Lee, Jae-Wuk, Doohwan Kim, and Jang-Eui Hong. "Code Refactoring Techniques Based on Energy Bad Smells for Reducing Energy Consumption." KIPS Transactions on Software and Data Engineering 5, no. 5 (May 31, 2016): 209–20. http://dx.doi.org/10.3745/ktsde.2016.5.5.209.

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Hastings, Mathew B. "Small Majorana fermion codes." Quantum Information and Computation 17, no. 13&14 (November 2017): 1191–205. http://dx.doi.org/10.26421/qic17.13-14-7.

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We consider Majorana fermion stabilizer codes with small number of modes and distance. We give an upper bound on the number of logical qubits for distance 4 codes, and we construct Majorana fermion codes similar to the classical Hamming code that saturate this bound. We perform numerical studies and find other distance 4 and 6 codes that we conjecture have the largest possible number of logical qubits for the given number of physical Majorana modes. Some of these codes have more logical qubits than any Majorana fermion code derived from a qubit stabilizer code.

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Klappenecker, A. A., and M. Rotteler. "On the structure of nonstabilizer Cliford codes." Quantum Information and Computation 4, no. 2 (March 2004): 152–60. http://dx.doi.org/10.26421/4.2-7.

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Clifford codes are a class of quantum error control codes that form a natural generalization of stabilizer codes. These codes were introduced in 1996 by Knill, but only a single Clifford code was known, which was not already a stabilizer code. We derive a necessary and sufficient condition that allows one to decide when a Clifford code is a stabilizer code, and compile a table of all true Clifford codes for error groups of small order.

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Okamoto, Masanori, Toshihisa Ishida, and Ken-ichi Sawada. "ICONE15-10221 PASSIVE SAFETY SMALL REACTOR FOR DISTRIBUTED ENERGY SUPPLY : CORE BURN-UP PERFORMANCE WITH BORON MIXED COOLANT." Proceedings of the International Conference on Nuclear Engineering (ICONE) 2007.15 (2007): _ICONE1510. http://dx.doi.org/10.1299/jsmeicone.2007.15._icone1510_108.

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Di Cintio, Pierfrancesco, Mario Pasquato, Hyunwoo Kim, and Suk-Jin Yoon. "Introducing a new multi-particle collision method for the evolution of dense stellar systems." Astronomy & Astrophysics 649 (May 2021): A24. http://dx.doi.org/10.1051/0004-6361/202038784.

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Context. Stellar systems are broadly divided into collisional and non-collisional categories. While the latter are large-N systems with long relaxation timescales and can be simulated disregarding two-body interactions, either computationally expensive direct N-body simulations or approximate schemes are required to properly model the former. Large globular clusters and nuclear star clusters, with relaxation timescales of the order of a Hubble time, are small enough to display some collisional behaviour and big enough to be impossible to simulate with direct N-body codes and current hardware. Aims. We aim to introduce a new method to simulate collisional stellar systems and validate it by comparison with direct N-body codes on small-N simulations. Methods. The Multi-Particle Collision for Dense Stellar Systems (MPCDSS) code is a new code for evolving stellar systems with the multi-particle collision method. Such a method amounts to a stochastic collision rule that makes it possible to conserve the exact energy and momentum over a cluster of particles experiencing the collision. The code complexity scales with N log N in the number of particles. Unlike Monte Carlo codes, MPCDSS can easily model asymmetric, non-homogeneous, unrelaxed, and rotating systems, while allowing us to follow the orbits of individual stars. Results. We evolved small (N = 3.2 × 104) star clusters with MPCDSS and with the direct-summation code NBODY6, finding a similar evolution of key indicators. We then simulated different initial conditions in the 104 − 106 star range. Conclusions. MPCDSS bridges the gap between small collisional systems that can be simulated with direct N-body codes and large non-collisional systems. In principle, MPCDSS allows us to simulate globular clusters such as Ω Centauri and M 54, and even nuclear star clusters, which is beyond the limits of current direct N-body codes in terms of the number of particles.

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Zwanch, Karen, and Bridget Broome. "Crack the Code." Mathematics Teacher: Learning and Teaching PK-12 116, no. 3 (March 2023): 184–91. http://dx.doi.org/10.5951/mtlt.2022.0158.

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Aksan, N. "International Standard Problems and Small Break Loss-of-Coolant Accident (SBLOCA)." Science and Technology of Nuclear Installations 2008 (2008): 1–22. http://dx.doi.org/10.1155/2008/814572.

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Best-estimate thermal-hydraulic system codes are widely used to perform safety and licensing analyses of nuclear power plants and also used in the design of advance reactors. Evaluation of the capabilities and the performance of these codes can be accomplished by comparing the code predictions with measured experimental data obtained on different test facilities. OECD/NEA Committee on the Safety of Nuclear Installations (CSNI) has promoted, over the last twenty-nine years, some forty-eight international standard problems (ISPs). These ISPs were performed in different fields as in-vessel thermal-hydraulic behaviour, fuel behaviour under accident conditions, fission product release and transport, core/concrete interactions, hydrogen distribution and mixing, containment thermal-hydraulic behaviour. 80% of these ISPs were related to the working domain of principal working group no.2 on coolant system behaviour (PWG2) and were one of the major PWG2 activities for many years. A global review and synthesis on the contribution that ISPs have made to address nuclear reactor safety issues was initiated by CSNI-PWG2 and an overview on the subject of small break LOCA ISPs is given in this paper based on a report prepared by a writing group. In addition, the relevance of small break LOCA in a PWR with relation to nuclear reactor safety and the reorientation of the reactor safety program after TMI-2 accident are shortly summarized. The experiments in four integral test facilities, LOBI, SPES, BETHSY, ROSA IV/LSTF and the recorded data during a steam generator tube rupture transient in the DOEL-2 PWR (Belgium) were the basis of the five small break LOCA related ISP exercises, which deal with the phenomenon typical of small break LOCAs in Western design PWRs. Some lessons learned from these small break LOCA ISPs are identified in relation to code deficiencies and capabilities, progress in the code capabilities, possibility of scaling, and various additional aspects. ISPs are providing unique material and benefits for some safety-related issues.

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Chen, Hongxiang, Michael Vasmer, Nikolas P. Breuckmann, and Edward Grant. "Automated discovery of logical gates for quantum error correction (with Supplementary (153 pages))." Quantum Information and Computation 22, no. 11&12 (August 2022): 947–64. http://dx.doi.org/10.26421/qic22.11-12-3.

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Quantum error correcting codes protect quantum computation from errors caused by decoherence and other noise. Here we study the problem of designing logical operations for quantum error correcting codes. We present an automated procedure that generates logical operations given known encoding and correcting procedures. Our technique is to use variational circuits for learning both the logical gates and the physical operations implementing them. This procedure can be implemented on near-term quantum computers via quantum process tomography. It enables automatic discovery of logical gates from analytically designed error correcting codes and can be extended to error correcting codes found by numerical optimization. We test the procedure by simulating small quantum codes of four to fifteen qubits showing that our procedure finds most logical gates known in the current literature. Additionally, it generates logical gates not found in the current literature for the [[5,1,2]] code, the [[6,3,2]] code, the [[8,3,2]] code, and the [[10,1,2]] code.

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Seungsu, Yuk, Tak Nam-il, and Chang Jo Keun. "DEVELOPMENT OF PIN-LEVEL NEUTRONICS/THERMAL-FLUID ANALYSIS COUPLED CODE SYSTEM FOR A BLOCK-TYPE HTGR CORE." EPJ Web of Conferences 247 (2021): 02041. http://dx.doi.org/10.1051/epjconf/202124702041.

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Recently, the coupling between computer codes that simulate different physical phenomena has attracted for more accurate analysis. In the case of high-temperature gas-cooled reactor (HTGR), the coupling between neutronics and thermal-fluid analysis is necessary because of large change of temperature in the reactor core. Korea Atomic Energy Research Institute (KAERI) has developed the coupled code system between a reactor physics analysis code CAPP and a thermal-fluid system safety analysis code GAMMA+ for a block-type HTGR. The CAPP/GAMMA+ coupled code system provides more accurate block-wise distribution data than CAPP or GAMMA+ stand-alone analysis. However, the block-wise distribution data has the limitation in order to predict safety parameters such as the maximum temperature of the nuclear fuel. It is necessary to calculate refined distribution, for example, pin-level (fuel compact level) distribution. In this study, we tried to solve this problem by coupling CAPP and a high-fidelity thermal-fluid analysis code CORONA. CORONA can perform a high-fidelity thermal-fluid analysis of Computational Fluid Dynamics (CFD) level by dividing a block-type HTGR core into small lattices. On the other hand, CAPP can provide a pin power distribution. It is expected that the refined, more accurate distribution data for a block-type HTGR can be obtained by coupling these two codes. This paper presents the development of coupled code system between CAPP and CORONA, and then it is tested on a simple HTGR column problem with encouraging results.

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Bird, Robert F., Patrick Gillies, Michael R. Bareford, Andy Herdman, and Stephen Jarvis. "Performance Optimisation of Inertial Confinement Fusion Codes using Mini-applications." International Journal of High Performance Computing Applications 32, no. 4 (November 2, 2016): 570–81. http://dx.doi.org/10.1177/1094342016670225.

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Despite the recent successes of nuclear energy researchers, the scientific community still remains some distance from being able to create controlled, self-sustaining fusion reactions. Inertial Confinement Fusion (ICF) techniques represent one possible option to surpass this barrier, with scientific simulation playing a leading role in guiding and supporting their development. The simulation of such techniques allows for safe and efficient investigation of laser design and pulse shaping, as well as providing insight into the reaction as a whole. The research presented here focuses on the simulation code EPOCH, a fully relativistic particle-in-cell plasma physics code concerned with faithfully recreating laser-plasma interactions at scale. A significant challenge in developing large codes like EPOCH is maintaining effective scientific delivery on successive generations of high-performance computing architecture. To support this process, we adopt the use of mini-applications – small code proxies that encapsulate important computational properties of their larger parent counterparts. Through the development of a mini-application for EPOCH (called miniEPOCH), we investigate a variety of the performance features exhibited in EPOCH, expose opportunities for optimisation and increased scientific capability, and offer our conclusions to guide future changes to similar ICF codes.

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Dubey, Anshu, Petros Tzeferacos, and Don Q. Lamb. "The dividends of investing in computational software design: A case study." International Journal of High Performance Computing Applications 33, no. 2 (December 21, 2017): 322–31. http://dx.doi.org/10.1177/1094342017747692.

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A significant fraction of computational software for scientific research grows through accretion. In a common scenario, a small group develops a code for a specific purpose. Others find the software useful, so they add to it for their own use. The software grows to the point where its management becomes intractable and scientific results obtained from it become unreliable. This is in stark contrast with a small number of scientific codes that have undergone a design process, be it due to an upfront investment, or when haphazardly grown codes have reset and started again. At a minimum, these codes reduce the time to obtain research results for the communities they serve because individual researchers do not have to develop their own codes. They provide further benefits; the results they produce are more reproducible due to greater scrutiny, leading to better science. One of the more overlooked benefits, which is perhaps of greater significance, is that a well-designed code can expand to serve communities beyond the ones it was designed for. Thus, research communities with similar computational requirements can symbiotically improve computation-based research for each other. In this article, we present a case study of FLASH, a code that was designed and developed for simulating thermonuclear runaways such as novae and type Ia supernovae in astrophysics. Designed to be modular and extensible, users from several diverse research areas have added capabilities to it and adapted it for their own communities. Examples include cosmology, high-energy density physics, core-collapse supernovae, star formation, fluid–structure interactions, and chemical combustion. We give a summary of design features that facilitated the expansion and quantify the effort needed to expand into some of the above-mentioned fields. We also quantify the impact on different communities by mining the database of publications using FLASH, collected by its developers.

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Milosevic, Miodrag, Ehud Greenspan, and Jasmina Vujic. "Monte Carlo with fuel burnup method for the ENHS benchmark calculations." Nuclear Technology and Radiation Protection 18, no. 2 (2003): 3–11. http://dx.doi.org/10.2298/ntrp0302003m.

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Estimates of the uncertainties arising from approximations in the methods used in different nuclear data processing and neutron transport codes are usually obtained by inter-comparing calculations made using different code systems. This paper gives details of an investigation of differences between results obtained by using different codes for a single zone model of the Encapsulated Nuclear Heat Source (ENHS) benchmark core fuelled with metallic alloy of Pu, U, and Zr. The ENHS is a new lead-bismuth or lead cooled novel reactor concept for 20 effective full power years without refuelling and with very small reactivity swing. The computational tools benchmarked include MOCUP, a coupled MCNP-4C and ORIGEN2.1 utility codes with MCNP data libraries based on ENDF/B-VI evaluation; KENO-V.a/ORIGEN2.1 code system, recently developed by authors of this paper, with the ENDFB-V based 238 group library; the design-oriented procedure based on the simplified one-dimensional (1D) geometry model and SAS2H control module; and the well-established fast reactor neutronics design tools in use at Argonne National Laboratory. Calculations made for the ENHS benchmark have shown that the differences between the results obtained when using different code schemes are quite significant and should be taken into account in assessing the quality of the nuclear data library.

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Jiao, Dawei, and Ying Li. "Fault-tolerant fidelity based on few-qubit codes: parity-check circuits for biased error operators." Quantum Information and Computation 22, no. 5&6 (April 2022): 408–26. http://dx.doi.org/10.26421/qic22.5-6-3.

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In the shallow sub-threshold regime, fault-tolerant quantum computation requires a tremendous amount of qubits. In this paper, we study the error correction in the deep sub-threshold regime. We estimate the physical error rate for achieving the logical error rates of $10^{-6} - 10^{-15}$ using few-qubit codes, i.e.~short repetition codes, small surface codes and the Steane code. Error correction circuits that are efficient for biased error operators are identified. Using the Steane code, when error operators are biased with a ratio of $10^{-3}$, the logical error rate of $10^{-15}$ can be achieved with the physical error rate of $10^{-5}$, which is much higher than the physical error rate of $10^{-9}$ for depolarising errors.

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Kromar, Marjan, and Bojan Kurinčič. "Comparison of the SCALE, SERPENT and MCNP Criticality Safety Calculation of the NPP Krško Spent Fuel Pool." Journal of Energy - Energija 62, no. 1-4 (July 18, 2022): 200–208. http://dx.doi.org/10.37798/2013621-4230.

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Criticality safety reanalyzes of the NPP Krško spent fuel pool has been performed. Limiting criticality cases at optimal moderation conditions are calculated using different SCALE code versions (SCALE-4.4a, SCALE-5.1 and SCALE-6.1) with 44-group ENDF/B-V and 238-group ENDF/B-VII.0 derived cross section libraries. Relative small discrepancies are observed. Additional verification is provided with SERPENT and MCNP5 codes, which are capable to take into account neutron continuous energy cross section library based on ENDF/B-VII.0 files. Comparison has shown that the results of the pool design calculations are conservative, precluding racks criticality even at optimum moderation conditions.

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Cruz, Luis, and Rui Abreu. "Improving Energy Efficiency Through Automatic Refactoring." Journal of Software Engineering Research and Development 7 (August 17, 2019): 2. http://dx.doi.org/10.5753/jserd.2019.17.

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The ever-growing popularity of mobile phones has brought additional challenges to the software development lifecycle. Mobile applications ought to provide the same set of features as conventional software, with limited resources: such as limited processing capabilities, storage, screen and, not less important, power source. Although energy efficiency is a valuable requirement, developers often lack knowledge of best practices. In this paper, we propose a tool to improve the energy efficiency of Android applications using automatic refactoring — Leafactor. The tool features five energy code smells that tend to go unnoticed. In addition, we study whether automatic refactoring can aid developers to ship energy efficient mobile applications with a dataset of 140 free and open source apps. As a result, we detect and fix code smells in 45 Android apps, from which 40% have successfully merged our changes into the official repository.

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Zhang, Xue Bin, Qiong Wan, and Zhi Gang Li. "Hourglass Control Methods in Numerical Simulation Code RingForm." Advanced Materials Research 378-379 (October 2011): 35–38. http://dx.doi.org/10.4028/www.scientific.net/amr.378-379.35.

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Hourglass is obviously aroused in cold ring rolling simulation with reduced integration element because of ring vibrating violently and small contact area of ring and rollers. In the developed numerical simulation code named RingForm, two methods are used to control the hourglass. The first method is combination of artificial damping and artificial stiffness. The second is one-point quadrature element with hourglass control, which need not user-defined control parameters. Hourglass energy can be reduced to 3 percent of the internal energy. Using the latter, good elements are acquired, while computational efficiency is obviously lower than the former.

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Palomba, Fabio, Dario Di Nucci, Annibale Panichella, Andy Zaidman, and Andrea De Lucia. "On the impact of code smells on the energy consumption of mobile applications." Information and Software Technology 105 (January 2019): 43–55. http://dx.doi.org/10.1016/j.infsof.2018.08.004.

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Seubert, A. "A 3-D FINITE ELEMENT FEW-GROUP DIFFUSION CODE AND ITS APPLICATION TO GENERATION IV REACTOR CONCEPTS." EPJ Web of Conferences 247 (2021): 02010. http://dx.doi.org/10.1051/epjconf/202124702010.

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In this paper, a recently developed 3-d few-group finite element-based diffusion code is de-scribed. Its geometrical flexibility allows future modeling of complex and irregular geometries of (very) small and medium size reactor concepts –(v)SMRs –being in the spotlight for energy provision in remote residential and industrial regions or for space applications, and also liquid metal cooled Generation IV reactors where thermally induced core deformation results in localized assembly lattice distortions which cannot be treated by traditional 3-d neutron kinetics codes devoted to the regular lattices of LWR and Generation IV systems. The description of the implemented FEM solution method is followed by first applications to a prismatic (or block type) high-temperature reactor MHTGR-350MW within an OECD/NEA benchmark activity and to the sodium cooled fast reactor concept ASTRID within the past EU project ESNII+. Finally, an outlook to planned further code development activities is given.

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Choe, Jiwon, Chirayu Batra, Vladimir Kriventsev, and Deokjung Lee. "Neutronic Analysis of Start-Up Tests at China Experimental Fast Reactor." Energies 15, no. 3 (February 8, 2022): 1249. http://dx.doi.org/10.3390/en15031249.

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The China Experimental Fast Reactor (CEFR) is a small, sodium-cooled fast reactor with 20 MW(e) of power. Start-up tests of the CEFR were performed from 2010 to 2011. The China Institute of Atomic Energy made some of the neutronics start-up-test data available to the International Atomic Energy Agency (IAEA) as part of an international neutronics benchmarking exercise by distributing the experimental data to interested organizations from the member states of the IAEA. This benchmarking aims to validate and verify the physical models and neutronics simulation codes with the help of the recorded experimental data. The six start-up tests include evaluating criticality, control-rod worth, reactivity effects, and neutron spectral characteristics. As part of this coordinated research, the IAEA performed neutronics calculations using the Monte Carlo codes Serpent 2 and OpenMC, which can minimize modeling assumptions and produce reference solutions for code verification. Both codes model a three-dimensional heterogeneous core with an ENDF/B-VII.1 cross-section library. This study presents the calculation results with a well-estimated criticality and a reasonably good estimation of reactivities. The description and analysis of the core modeling assumptions, challenges in modeling a dense SFR core, results of the first phase of this project, and comparative analysis with measurements are presented.

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Liu, Xiao, Mianxiong Dong, Yuxin Liu, Anfeng Liu, and Neal N. Xiong. "Construction Low Complexity and Low Delay CDS for Big Data Code Dissemination." Complexity 2018 (June 20, 2018): 1–19. http://dx.doi.org/10.1155/2018/5429546.

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The diffusion of codes is an important processing technology for big data networks. In previous scheme, data analysis was conducted for small samples of big data and complex problems that cannot be processed by big data technology. Due to the limited capacity of intelligence device, a better method is to select a set of nodes (intelligence device) to form a connected dominating set (CDS) to save energy, and constructing CDS is proved to be a complete NP problem. However, it is a challenge to reduce the communication delay and complexity for urgent data transmission in big data. In this paper, an appropriate duty cycle control (ADCC) scheme is proposed to reduce communication delay and complexity while improving energy efficient in CDS-based WSNs. In ADCC scheme, the method for constructing CDS is proposed at lower complexity. Nodes in CDS are selected according to the degree of nodes. Then, duty cycle of dominator nodes in CDS is higher than that of dominated nodes, so the communication delay in the proposed scheme is far less than that of previous scheme. The duty cycle of dominated nodes is small to save energy. This is because the number of dominator nodes in CDS is far less than the number of dominated nodes whose duty cycle is small; thus, the total energy consumption of the network is less than that of the previous scheme. As a result, the performance of energy consumption and communication delay and complex have been improved. Its complexity O∑i=0vm−i+2m−2v−s is reduced a lot for big data. The theoretical analysis shows that compared to the previous scheme, the transmission delay can be reduced 25–92% and the energy efficiency is improved by about 80% while retaining network lifetime.

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Mavko, Borut, Andrej Prošek, and Francesco D’auria. "Determination of Code Accuracy in Predicting Small-Break LOCA Experiment." Nuclear Technology 120, no. 1 (October 1997): 1–18. http://dx.doi.org/10.13182/nt97-a35427.

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Khan, Baseem, Josep M. Guerrero, Sanjay Chaudhary, Juan C. Vasquez, Kenn H. B. Frederiksen, and Ying Wu. "A Review of Grid Code Requirements for the Integration of Renewable Energy Sources in Ethiopia." Energies 15, no. 14 (July 18, 2022): 5197. http://dx.doi.org/10.3390/en15145197.

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Rapid integration of renewable energy into the electric grid has ramifications for grid management and planning. Therefore, system operators have formulated grid code requirements to ensure that the grid continues to operate in a secure, safe, and cost-effective manner. The current state of grid code in Ethiopia, as well as the need for it, is discussed in this article. It lays out the technological grid integration requirements, with a focus on small and microgrids, which are especially important for the integration of renewable. The barriers to grid code normalization and renewable energy grid compatibility testing are identified, and suggestions for continued grid code development in Ethiopia based on Danish observations are provided. Further, a detailed comparative analysis of the Ethiopian grid code with the IEEE 1547-2003 and IEEE 1547-2018 standards is presented.

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ISHIKAWA, Hirohiko, and Masamichi CHINO. "Development of three-dimensional atmospheric dispersion code for small scale computer." Journal of the Atomic Energy Society of Japan / Atomic Energy Society of Japan 30, no. 4 (1988): 350–58. http://dx.doi.org/10.3327/jaesj.30.350.

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Villalba, Isabel, Marcos Blanco, Juan I. Pérez‐Díaz, Daniel Fernández, Felipe Díaz, and Marcos Lafoz. "Wave farms grid code compliance in isolated small power systems." IET Renewable Power Generation 13, no. 1 (November 9, 2018): 171–79. http://dx.doi.org/10.1049/iet-rpg.2018.5351.

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Sung Lim, Hyun, In Ho Ryu, and Jun Ho Bang. "IOT based modeling of closed transition transfer switch in IEC 61850." International Journal of Engineering & Technology 7, no. 2.12 (April 3, 2018): 329. http://dx.doi.org/10.14419/ijet.v7i2.12.11317.

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Background/Objectives: The power demand of utility electrical power has stimulated the use of distributed energy for peak shaving. Distributed energy resources need to be monitored and controlled like Internet of Things.Methods/Statistical analysis: Distributed Energy Resources (DERs) are small scale electric energy system like Micro Turbine, Photovoltaic, Wind power, Small Generator and widely spread in Korea. For utilizing electrical device with Internet of Things, we need integrated system and adapt International Electrical Code like IEC 61850.Findings: To connect DERs with uninterrupted grid system, it required Closed Transition Transfer Switch (CTTS). Existing International Electrical Code presented some distributed energy resource by IEC 61850-7-420. However, the switch like CTTS is not presented. So, we described modeling of CTTS in IEC 61850 and verified monitoring data with TCP/IP.Improvements/Applications: The proposed modeling of CTTS not only combines the DERs with grid system but also conjugates smart grid system with IOT Technology.

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Taubin, F. A. "MULTIPLE ACCESS IN WIRELESS CHANNELS USING NONORTHOGONAL CODING AND FREQUENCY INTERLEAVING." System analysis and logistics 4, no. 34 (December 20, 2022): 73–82. http://dx.doi.org/10.31799/2077-5687-2022-4-73-82.

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Code division multiple access (CDMA) is currently considered as one of the promising technologies that can significantly improve the efficiency of modern and future communication networks. In code division multiple access systems, users can share a dedicated space-frequency-time resource to simultaneously transmit their own traffic. To ensure the separation of individual user streams on the receiving side, each user is provided with his own code sequence embedded in the broadband signal transmitted by this user, the spectrum of which, as a rule, occupies the entire allocated frequency band. When centimeter-and- millimeter wave wireless channels are used as the transmission medium, such factors as fading, multipath, and Doppler scatter can significantly degrade the performance of a code division multiple access system. The standard solution in this situation is to combine code division multiple access with OFDM (orthogonal frequency division multiplexing) technology, known as multicarrier CDMA (MC-CDMA). To ensure the acceptable level of performance of multiple access systems under oversaturated conditions, many novel approaches based on the use of non-orthogonal multiple access (NOMA) have been proposed. The paper considers a variant of multiple access with non-orthogonal coding that is close in approach to sparse coding multiple access (SCMA). The proposed access procedure is based on dividing the allocated time-frequency resource into relatively small clusters and sharing each cluster with its own group of users, equipped with a non-orthogonal cluster code with the ability to change the loading factor. For the proposed class of cluster codes, a general encoding and decoding scheme is presented. Examples of specific cluster code constructions and numerical results are given that allow one to get a number of the parameters for tradeoffs between an increase of the loading factor in the system and additional energy loss.

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Lee, S. "Developing a plasma focus research training system for the fusion energy age." International Journal of Modern Physics: Conference Series 32 (January 2014): 1460313. http://dx.doi.org/10.1142/s2010194514603135.

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The 3 kJ UNU/ICTP Plasma Focus Facility is the most significant device associated with the AAAPT (Asian African Association for Plasma Training). In original and modified/upgraded form it has trained generations of plasma focus (PF) researchers internationally, producing many PhD theses and peer-reviewed papers. The Lee Model code was developed for the design of this PF. This code has evolved to cover all PF machines for design, interpretation and optimization, for derivation of radiation scaling laws; and to provide insights into yield scaling limitations, radiative collapse, speed-enhanced and current-stepped PF variants. As example of fresh perspectives derivable from this code, this paper presents new results on energy transfers of the axial and radial phases of generalized PF devices. As the world moves inexorably towards the Fusion Energy Age it becomes ever more important to train plasma fusion researchers. A recent workshop in Nepal shows that demand for such training continues. Even commercial project development consultants are showing interest. We propose that the AAAPT-proven research package be upgraded, by modernizing the small PF for extreme modes of operation, switchable from the typical strong-focus mode to a slow-mode which barely pinches, thus producing a larger, more uniform plasma stream with superior deposition properties. Such a small device would be cost-effective and easily duplicated, and have the versatility of a range of experiments from intense multi-radiation generation and target damage studies to superior advanced-materials deposition. The complementary code is used to reference experiments up to the largest existing machine. This is ideal for studying machine limitations and scaling laws and to suggest new experiments. Such a modernized versatile PF machine complemented by the universally versatile code would extend the utility of the PF experience; so that AAAPT continues to provide leadership in pulsed plasma research training in preparation for the Fusion Energy Age.

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Zhuravlev, I. M., and A. V. Osipov. "Resonant solar cell energy converter in the power supply system for small spacecraft." Proceedings of Tomsk State University of Control Systems and Radioelectronics 23, no. 3 (September 25, 2020): 81–85. http://dx.doi.org/10.21293/1818-0442-2020-23-3-81-85.

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The operation of a solar cell resonant converter at operating modes in the power supply system of a small spacecraft is investigated. The resonant converter with pulse-code regulation simulation model has been developed, and the operation point by stabilizing charge current mode and stabilizing output voltage mode is considered. The converter regulating characteristics in various operating modes are obtained.

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Adi Wiguna Sanjaya, I. Kadek, Nyoman Pramaita, and I. Made Oka Widyantara. "DESAIN SIMULASI UNJUK KERJA KODE SMALL KASAMI PADA KANAL MULTIPATH FADING." Jurnal SPEKTRUM 8, no. 3 (October 1, 2021): 29. http://dx.doi.org/10.24843/spektrum.2021.v08.i03.p4.

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Telecommunication capable of handling interference, fading and no less importantissues regarding the confidentiality of user information is very much needed in the currenttechnological era, to overcome this spread spectrum technology is quite developed in theadvancement of telecommunication technology. In this study, the small kasami code was usedas the spreading code. The purpose of this study is to determine the performance of the smallkasami code with changes in the number of multipath components using multipath fadingchannels. The modulation technique uses digital modulation, namely binary phase shift keying(BPSK) with a small kasami code with a code length of 15 in the spreading and spreadingprocess. Analyzed based on BER (Bit Error Rate) versus EB/No (Energy Bit per Noise). In thesimulation of flat fading performance using 1 multipath component, flat fading serves as an idealreference where the simulation BER should resemble the theoretical BER as simulationvalidation so that it can be used on selective fading channels. Variation of multipathcomponents in frequency selective fading channel produces different BER because there isinterference of multipath signal to the desired signal. The number of multipath components asmany as 11 have the most interference signals resulting in the worst performance. The value ofcross correlation between users has poor performance, where the correlation value of user 1with 2, 3, and 4 is more than 0, this value shows that many signal levels experience interferencebetween users.

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Ghal-Eh, N., M. Aliannezhadi, and S. V. Bedenko. "Optical photon transport and geometry contributions to time response of scintillation detectors." International Journal of Modern Physics C 29, no. 09 (September 2018): 1850091. http://dx.doi.org/10.1142/s0129183118500912.

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The sensitivities of both time and energy resolutions of a typical scintillation detector to major optical parameters (i.e. paint reflectivity, quantum efficiency of photomultiplier tube and attenuation coefficient) have been estimated using a dedicated Monte Carlo (MC) optical photon transport (OPT) simulation code, PHOTRACK, and the OPT capabilities of general-purpose code, FLUKA. Both cylindrical and parallelepiped geometries have been considered for the scintillator cell and lightguide. The results determine the scintillation light wavelength regions that the energy and time resolution represent enhanced sensitivities to small change/uncertainty in optical parameters.

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Dilmi, S., and A. Boumali. "Estimation of Electron Impact Ionization Rates of Li Using a Non-Maxwellian Distribution Function." Ukrainian Journal of Physics 66, no. 8 (September 8, 2021): 691. http://dx.doi.org/10.15407/ujpe66.8.691.

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We report an estimate of the cross-section and rate of electron-impact ionization of Li. The FAC code (Flexible Atomic Code) is used in order to determine the cross-section and to calculate the level of energy. We evaluate the effect of electron energy distribution functions on the measurement of the ionization rate for a non-Maxwellian energy distribution, if the fraction of hot electrons is small. In several types of plasma, it has been observed that certain (hot) electrons are governed by a non-Maxwellian energy distribution. These electrons affect the line spectra and other characteristics of plasma. By using a non-Maxwellian distribution of energies, we revealed the sensitivity of the electron-impact ionization rate of Li to types of the electron energy distribution and to the fraction of hot electrons.

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Hwang, Dae Hee, and Ser Gi Hong. "SMALL MODULAR PWR DESIGN FOR TRU RECYCLING WITH McCARD-MASTER TWO-STEP PROCEDURE." EPJ Web of Conferences 247 (2021): 01003. http://dx.doi.org/10.1051/epjconf/202124701003.

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In our previous study, a small modular PWR core was designed for TRU (Transuranics) recycling with multi-recycling scheme with a typical two-step procedure using DeCART2D/MASTER code system in which the lattice analysis for producing homogenized group constant was performed by DeCART2D while whole core analysis was conducted by MASTER code. However, the neutron spectrum hardening of the LWR core loaded with TRU requires validating the multi-group cross section library and resonance self-shielding treatment method in lattice calculation. In this study, a new procedure using McCARD/MASTER was used to analyze the SMR core, in which the lattice calculation was performed by a Monte Carlo code called McCARD with a continuous energy library to generate homogenized two-group assembly cross sections. The SMR core analysis was performed to show neutronic characteristics and TRU mass flow in the SMR core with TRU multi-recycling. The result shows that the analyses on the neutronic characteristics and TRU mass flow using the McCARD/MASTER code system showed good agreement with the previous ones using the DeCART2D/MASTER code system. The neutronic characteristics of each cycle of the core satisfied the typical limit of a commercial PWR core and the SMR core consumes effectively TRU with net TRU consumption rates of 8.46~14.33 %.

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Cotronei, Alessandro, and Thomas Slawig. "Single-precision arithmetic in ECHAM radiation reduces runtime and energy consumption." Geoscientific Model Development 13, no. 6 (June 24, 2020): 2783–804. http://dx.doi.org/10.5194/gmd-13-2783-2020.

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Abstract. We converted the radiation part of the atmospheric model ECHAM to a single-precision arithmetic. We analyzed different conversion strategies and finally used a step-by-step change in all modules, subroutines and functions. We found out that a small code portion still requires higher-precision arithmetic. We generated code that can be easily changed from double to single precision and vice versa, basically using a simple switch in one module. We compared the output of the single-precision version in the coarse resolution with observational data and with the original double-precision code. The results of both versions are comparable. We extensively tested different parallelization options with respect to the possible runtime reduction, at both coarse and low resolution. The single-precision radiation itself was accelerated by about 40 %, whereas the runtime reduction for the whole ECHAM model using the converted radiation achieved 18 % in the best configuration. We further measured the energy consumption, which could also be reduced.

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Freedman, Michael H., and Matthew B. Hastings. "Quantum Systems on Non-$k$-Hyperfinite Complexes: a generalization of classical statistical mechanics on expander graphs." Quantum Information and Computation 14, no. 1&2 (January 2014): 144–80. http://dx.doi.org/10.26421/qic14.1-2-9.

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We construct families of cell complexes that generalize expander graphs. These families are called non-$k$-hyperfinite, generalizing the idea of a non-hyperfinite (NH) family of graphs. Roughly speaking, such a complex has the property that one cannot remove a small fraction of points and be left with an object that looks $k-1$-dimensional at large scales. We then consider certain quantum systems on these complexes. A future goal is to construct a family of Hamiltonians such that every low energy state has topological order as part of an attempt to prove the quantum PCP conjecture. This goal is approached by constructing a toric code Hamiltonian with the property that every low energy state without vertex defects has topological order, a property that would not hold for any local system in any lattice $Z^d$ or indeed on any $1$-hyperfinite complex. Further, such NH complexes find application in quantum coding theory. The hypergraph product codes\cite{hpc} of Tillich and Z\'{e}mor are generalized using NH complexes.

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36

Kawanishi, K., A. Tsuge, K. Kuwabara, O. Ukai, and N. Nakamori. "Small break loch experiments and verification of CANAC-II code." Nuclear Engineering and Design 120, no. 2-3 (June 1990): 259–69. http://dx.doi.org/10.1016/0029-5493(90)90378-b.

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Li, Tao, Mehdi Ashraphijuo, Xiaodong Wang, and Pingyi Fan. "Traffic Off-Loading With Energy-Harvesting Small Cells and Coded Content Caching." IEEE Transactions on Communications 65, no. 2 (February 2017): 906–17. http://dx.doi.org/10.1109/tcomm.2016.2636283.

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Johnson, Seth R., Stefano C. Tognini, Philippe Canal, Thomas Evans, Soon Yung Jun, Guilherme Lima, Amanda Lund, and Vincent R. Pascuzzi. "Novel features and GPU performance analysis for EM particle transport in the Celeritas code." EPJ Web of Conferences 251 (2021): 03030. http://dx.doi.org/10.1051/epjconf/202125103030.

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Celeritas is a new computational transport code designed for high-performance simulation of high-energy physics detectors. This work describes some of its current capabilities and the design choices that enable the rapid development of efficient on-device physics. The abstractions that underpin the code design facilitate low-level performance tweaks that require no changes to the higher-level physics code. We evaluate a set of independent changes that together yield an almost 40% speedup over the original GPU code for a net performance increase of 220× for a single GPU over a single CPU running 8.4M tracks on a small demonstration physics app.

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Kim, Hyoung Tae, Bo Wook Rhee, and Joo Hwan Park. "A blind simulation of RD-14M small-break LOCA experiments using CATHENA code." Annals of Nuclear Energy 38, no. 2-3 (February 2011): 389–403. http://dx.doi.org/10.1016/j.anucene.2010.10.002.

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40

Házi, Gábor, Gusztáv Mayer, István Farkas, Péter Makovi, and A. A. El-Kafas. "Simulation of a small loss of coolant accident by using RETINA V1.0D code." Annals of Nuclear Energy 28, no. 16 (November 2001): 1583–94. http://dx.doi.org/10.1016/s0306-4549(01)00008-1.

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41

Mascari, F., G. Vella, B. G. Woods, and F. D'Auria. "Analyses of the OSU-MASLWR Experimental Test Facility." Science and Technology of Nuclear Installations 2012 (2012): 1–19. http://dx.doi.org/10.1155/2012/528241.

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Today, considering the sustainability of the nuclear technology in the energy mix policy of developing and developed countries, the international community starts the development of new advanced reactor designs. In this framework, Oregon State University (OSU) has constructed, a system level test facility to examine natural circulation phenomena of importance to multi-application small light water reactor (MASLWR) design, a small modular pressurized water reactor (PWR), relying on natural circulation during both steady-state and transient operation. The target of this paper is to give a review of the main characteristics of the experimental facility, to analyse the main phenomena characterizing the tests already performed, the potential transients that could be investigated in the facility, and to describe the current IAEA International Collaborative Standard Problem that is being hosted at OSU and the experimental data will be collected at the OSU-MASLWR test facility. A summary of the best estimate thermal hydraulic system code analyses, already performed, to analyze the codes capability in predicting the phenomena typical of the MASLWR prototype, thermal hydraulically characterized in the OSU-MASLWR facility, is presented as well.

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Agudelo Rueda, Jeffersson A., Daniel Verscharen, Robert T. Wicks, Christopher J. Owen, Georgios Nicolaou, Kai Germaschewski, Andrew P. Walsh, Ioannis Zouganelis, and Santiago Vargas Domínguez. "Energy Transport during 3D Small-scale Reconnection Driven by Anisotropic Plasma Turbulence." Astrophysical Journal 938, no. 1 (October 1, 2022): 4. http://dx.doi.org/10.3847/1538-4357/ac8667.

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Abstract Energy dissipation in collisionless plasmas is a long-standing fundamental physics problem. Although it is well known that magnetic reconnection and turbulence are coupled and transport energy from system-size scales to subproton scales, the details of the energy distribution and energy dissipation channels remain poorly understood. Especially, the energy transfer and transport associated with 3D small-scale reconnection that occurs as a consequence of a turbulent cascade is unknown. We use an explicit fully kinetic particle-in-cell code to simulate 3D small-scale magnetic reconnection events forming in anisotropic and decaying Alfvénic turbulence. We identify a highly dynamic and asymmetric reconnection event that involves two reconnecting flux ropes. We use a two-fluid approach based on the Boltzmann equation to study the spatial energy transfer associated with the reconnection event and compare the power density terms in the two-fluid energy equations with standard energy-based damping, heating, and dissipation proxies. Our findings suggest that the electron bulk flow transports thermal energy density more efficiently than kinetic energy density. Moreover, in our turbulent reconnection event, the energy density transfer is dominated by plasma compression. This is consistent with turbulent current sheets and turbulent reconnection events, but not with laminar reconnection.

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Hwang, Seokha, Seungsik Moon, Dongyun Kam, Inn-Yeal Oh, and Youngjoo Lee. "High-Throughput and Low-Latency Digital Baseband Architecture for Energy-Efficient Wireless VR Systems." Electronics 8, no. 7 (July 22, 2019): 815. http://dx.doi.org/10.3390/electronics8070815.

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This paper presents a novel baseband architecture that supports high-speed wireless VR solutions using 60 GHz RF circuits. Based on the experimental observations by our previous 60 GHz transceiver circuits, the efficient baseband architecture is proposed to enhance the quality of transmission. To achieve a zero-latency transmission, we define an (106,920, 95,040) interleaved-BCH error-correction code (ECC), which removes iterative processing steps in the previous LDPC ECC standardized for the near-field wireless communication. Introducing the block-level interleaving, the proposed baseband processing successfully scatters the existing burst errors to the small-sized component codes, and recovers up to 1080 consecutive bit errors in a data frame of 106,920 bits. To support the high-speed wireless VR system, we also design the massive-parallel BCH encoder and decoder, which is tightly connected to the block-level interleaver and de-interleaver. Including the high-speed analog interfaces for the external devices, the proposed baseband architecture is designed in 65 nm CMOS, supporting a data rate of up to 12.8 Gbps. Experimental results show that the proposed wireless VR solution can transfer up to 4 K high-resolution video streams without using time-consuming compression and decompression, successfully achieving a transfer latency of 1 ms.

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Garzon, Max H., and Kiran C. Bobba. "Geometric Approaches to Gibbs Energy Landscapes and DNA Oligonucleotide Design." International Journal of Nanotechnology and Molecular Computation 3, no. 3 (July 2011): 42–56. http://dx.doi.org/10.4018/ijnmc.2011070104.

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DNA codeword design has been a fundamental problem since the early days of DNA computing. The problem calls for finding large sets of single DNA strands that do not crosshybridize to themselves, to each other or to others' complements. Such strands represent so-called domains, particularly in the language of chemical reaction networks (CRNs). The problem has shown to be of interest in other areas as well, including DNA memories and phylogenetic analyses because of their error correction and prevention properties. In prior work, a theoretical framework to analyze this problem has been developed and natural and simple versions of Codeword Design have been shown to be NP-complete using any single reasonable metric that approximates the Gibbs energy, thus practically making it very difficult to find any general procedure for finding such maximal sets exactly and efficiently. In this framework, codeword design is partially reduced to finding large sets of strands maximally separated in DNA spaces and, therefore, the size of such sets depends on the geometry of these spaces. Here, the authors describe in detail a new general technique to embed them in Euclidean spaces in such a way that oligonucleotides with high (low, respectively) hybridization affinity are mapped to neighboring (remote, respectively) points in a geometric lattice. This embedding materializes long-held metaphors about codeword design in analogies with error-correcting code design in information theory in terms of sphere packing and leads to designs that are in some cases known to be provably nearly optimal for small oligonucleotide sizes, whenever the corresponding spherical codes in Euclidean spaces are known to be so. It also leads to upper and lower bounds on estimates of the size of optimal codes of size under 20-mers, as well as to a few infinite families of DNA strand lengths, based on estimates of the kissing (or contact) number for sphere codes in high-dimensional Euclidean spaces. Conversely, the authors show how solutions to DNA codeword design obtained by experimental or other means can also provide solutions to difficult spherical packing geometric problems via these approaches. Finally, the reduction suggests a tool to provide some insight into the approximate structure of the Gibbs energy landscapes, which play a primary role in the design and implementation of biomolecular programs.

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Bornemisza, T., and A. Saith. "SPSLIFE: A User-Friendly Approach to the Structural Design and Life Assessment of Ceramic Components." Journal of Engineering for Gas Turbines and Power 118, no. 1 (January 1, 1996): 179–83. http://dx.doi.org/10.1115/1.2816536.

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In order to expedite the structural analysis of ceramic components, Sundstrand Power Systems has developed a proprietary computer code called “SPSLIFE,” which can substantially reduce the time spent on the design assessment of ceramic components. The life assessment computations for the various failure modes are performed using the structural analysis and materials files as input data. A number of “menus” are incorporated to request user input data and to guide the user through the problem definition process. The user has the capability to select existing material data files or create new ones. The computational modules are based on the analytical approaches currently used in the industry. The modular construction of the code facilitates making revisions or adding new modules. Graphic display is used to provide a visual summary of the life assessment calculations for the various failure modes. The output files generated provide a detailed review of the results, which is helpful for design optimization. Independently derived component fast fracture and static fatigue survival probabilities using the NASA CARES and CARES/LIFE codes are displayed for reference. The paper provides an application example using a patented design of a ceramic monorotor for the Sundstrand Power Systems TJ-50 small gas turbine engine.

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Kelsall, R. W. "Monte Carlo Simulations of Intersubband Hole Relaxation in a GaAs/AlAs Quantum Well." VLSI Design 8, no. 1-4 (January 1, 1998): 367–73. http://dx.doi.org/10.1155/1998/87925.

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An ensemble Monte Carlo code has been developed for the simulation of hole relaxation processes in a GaAs/AlAs quantum well. The code includes a realistic k.p model of the valence subbands and corresponding wavefunctions. Intra- and inter-subband phonon scattering rates are calculated for polar and non-polar interactions via both optical and acoustic modes. The code is used to simulate the cooling of non-equilibrium photogenerated hole populations. A lifetime of 90 fs is extracted for optical phonon mediated depopulation of the 4th subband at 77K. By contrast, the 2nd subband exhibits fast re-population, but slow de-population, with extracted lifetimes of up to 160 ps. The slow depopulation is attributed to the small energy separation of the 1st and 2nd subbands (less than the optical phonon energy) and the large density of states in the 2nd subband off-zone-centre minimum.

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47

Hoang, Van Khanh. "Core Design of a Small Pressurized Water Reactor with AP1000 Fuel Assembly Using SRAC and COBRA-EN Codes." Science and Technology of Nuclear Installations 2020 (November 10, 2020): 1–7. http://dx.doi.org/10.1155/2020/8847897.

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This paper presents the core design and performance characteristics of a 300 MWt small modular reactor (SMR) with fuel assemblies of the AP1000 reactor. Numerical calculations have been performed to evaluate a proper active core size and core loading pattern using the SRAC code system with the JENDL-4.0 data library and the CORBRA-EN code. The calculated temperature coefficients including fuel temperature, coolant temperature, and isothermal temperature coefficient provide adequate negative reactivity feedbacks. The thermal-hydraulic analysis reveals acceptable radial and axial fuel element temperature profiles with significant safety margin of fuel and clad surface temperature. A safety analysis using the CORBRA-EN code shows that the core will remain covered during the entire transient procedure of the fast transient of remarkably increasing power that would be caused by the ejection of control rod. The analysis results indicate that the core with a cycle length of 2.22 years is achievable while satisfying the operation and safety-related design criteria with sufficient margins.

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48

Kebede, Mekdes Gemechu, and Milkias Berhanu Tuka. "Power Control of Wind Energy Conversion System with Doubly Fed Induction Generator." Journal of Energy 2022 (November 7, 2022): 1–12. http://dx.doi.org/10.1155/2022/8679053.

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Wind power is one of the most efficient, reliable, and affordable renewable energy sources. The Doubly Fed Induction Generator (DFIG) is the most commonly used machine in wind power systems due to its small size power converter, reduced cost and losses, better quality, and the ability for independent power control. This research work deals with the power control of this machine by modeling and designing a suitable controller. Vector control is used to control the stator and grid active and reactive powers along with the proportional integral (PI) controller, fuzzy logic controller (FLC), and PI-fuzzy controllers. Modeling and simulation of the system are done using MATLAB Simulink, and the behavior of the machine with each controller is examined under variable wind speeds. Comparative analysis based on reference power tracking, stability, and grid code requirement fulfillment has been conducted. The obtained results show that among the three controllers, the PI-fuzzy controller meets the required specification with better performance, small oscillation, minimum overshoot, better reference tracking ability, and creating a stable and secure system by fulfilling grid code requirements. This study can be important to further insight into DFIG-based wind turbine systems.

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Martinez-Quiroga, V., and F. Reventos. "The Use of System Codes in Scaling Studies: Relevant Techniques for Qualifying NPP Nodalizations for Particular Scenarios." Science and Technology of Nuclear Installations 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/138745.

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System codes along with necessary nodalizations are valuable tools for thermal hydraulic safety analysis. Qualifying both codes and nodalizations is an essential step prior to their use in any significant study involving code calculations. Since most existing experimental data come from tests performed on the small scale, any qualification process must therefore address scale considerations. This paper describes the methodology developed at the Technical University of Catalonia in order to contribute to the qualification of Nuclear Power Plant nodalizations by means of scale disquisitions. The techniques that are presented include the so-calledKv-scaled calculation approach as well as the use of “hybrid nodalizations” and “scaled-up nodalizations.” These methods have revealed themselves to be very helpful in producing the required qualification and in promoting further improvements in nodalization. The paper explains both the concepts and the general guidelines of the method, while an accompanying paper will complete the presentation of the methodology as well as showing the results of the analysis of scaling discrepancies that appeared during the posttest simulations of PKL-LSTF counterpart tests performed on the PKL-III and ROSA-2 OECD/NEA Projects. Both articles together produce the complete description of the methodology that has been developed in the framework of the use of NPP nodalizations in the support to plant operation and control.

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Hatch, D. R., F. Jenko, V. Bratanov, and A. Bañón Navarro. "Phase space scales of free energy dissipation in gradient-driven gyrokinetic turbulence." Journal of Plasma Physics 80, no. 4 (May 6, 2014): 531–51. http://dx.doi.org/10.1017/s0022377814000154.

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A reduced four-dimensional (integrated over perpendicular velocity) gyrokinetic model of slab ion temperature gradient-driven turbulence is used to study the phase-space scales of free energy dissipation in a turbulent kinetic system over a broad range of background gradients and collision frequencies. Parallel velocity is expressed in terms of Hermite polynomials, allowing for a detailed study of the scales of free energy dynamics over the four-dimensional phase space. A fully spectral code – the DNA code – that solves this system is described. Hermite free energy spectra are significantly steeper than would be expected linearly, causing collisional dissipation to peak at large scales in velocity space even for arbitrarily small collisionality. A key cause of the steep Hermite spectra is acritical balance– an equilibration of the parallel streaming time and the nonlinear correlation time – that extends to high Hermite numbern. Although dissipation always peaks at large scales in all phase space dimensions, small-scale dissipation becomes important in an integrated sense when collisionality is low enough and/or nonlinear energy transfer is strong enough. Toroidal full-gyrokinetic simulations using theGenecode are used to verify results from the reduced model. Collision frequencies typically found in present-day experiments correspond to turbulence regimes slightly favoring large-scale dissipation, while turbulence in low-collisionality systems like ITER and space and astrophysical plasmas is expected to rely increasingly on small-scale dissipation mechanisms. This work is expected to inform gyrokinetic reduced modeling efforts like Large Eddy Simulation and gyrofluid techniques.

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Journal articles on the topic 'Energy Code Smell'

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